.box1 {
  width: 100px;
  height: 100px;
  color: red;
}
.box1:hover {
  color: aquamarine;
}
.box1 .box2 {
  background-color: skyblue;
}
.box1 .box2:hover {
  background-color: orange;
}
.box3,
.box4 {
  color: red;
}
.box4 {
  width: 100px;
  height: 100px;
}
.box7 {
  width: 200px;
  height: 200px;
  background-color: skyblue;
}
